Calibration was done with master flat and master bias frames in Astroart, then finally processed in Photoshop.
I've recently had a cataract removed from one of my eyes, and the change in colours is remarkable. I now realise that the old eye sees everything as through a yellow filter and the new eye is clear and without the filter. So blues are BLUE with the new eye but a greenish blue with the old. When the other eye's cataract has been removed I'll probably have to reprocess all my old photographs, and there are hundreds.